Japanese Laid-open Patent Publication No. 2013-45142 discloses an apparatus installed in a vehicle having a radar sensor on a rear portion thereof. The disclosed apparatus performs drive support control for reducing a probability of a collision between a host vehicle and a monitoring object passing behind the host vehicle from a left side thereof to a right side thereof or from the right side thereof to the left side thereof.
However, with respect to the drive support control as described above, accuracy of calculation based on the detection result of the radar sensor after an object is started to be detected may lead to a problem. This is because a probability that a position of a reflection point that defines a distance between the radar sensor and the object does not correspond to a position of a portion of the object that actually defines the minimum distance with respect to the radar sensor. Thus, during a period in which the reflection point (among possibly a plurality of reflection points on the object) that defines the distance between the radar sensor and the object moves on the object, after the object is started to be detected by the radar sensor, a moving direction of the object calculated based on the detection information of the object from the radar sensor may have an error with respect to an actual moving direction of an approaching vehicle.
Such a problem also occurs in a case of drive support control, in a vehicle having a radar sensor on a front portion thereof, for reducing a probability of a collision between the host vehicle and a monitoring object passing before the host vehicle from a left side thereof to a right side thereof or from the right side thereof to the left side thereof.
Therefore, an object of the disclosure is to at least partially reduce the problem described above.